In 2006, he played the starring role as Aquaman in a television pilot for The CW titled Aquaman (or Mercy Reef), but it was not picked up as a series. Hartley did a seven-episode run as billionaire Oliver Queen on the CW series Smallville later that year. In 2008, he returned to Smallville as a regular cast member, following the departures of Kristin Kreuk and Michael Rosenbaum.[5] Hartley also co-wrote the 2010 episode "Sacrifice" and directed the 2011 episode "Dominion".[citation needed]

In 2008, he starred as Tom in the film Red Canyon, filmed in the badlands of Utah.[6]

In 2003, Hartley began dating his Passions co-star Lindsay Korman (who played Theresa Lopez-Fitzgerald). After six months, the two became engaged on November 13, 2003, and on May 1, 2004, they married in a small ceremony. On July 3, 2004, Korman gave birth to their daughter.

On May 6, 2012, it was announced that Lindsay filed for divorce after eight years of marriage in the Los Angeles County Superior Court, citing "irreconcilable differences" and asking for joint physical and legal custody of their daughter.[13]

In 2014, he began dating actress Chrishell Stause[14] and in July 2016, they announced their engagement.[15] They were married on October 28, 2017.[16]